The objectives of this grant are the conduct of integrated, multi- departmental programs of mission oriented research in the diagnosis, management and pathophysiology of thrombotic and hemorrhagic diseases. We have established a core hemostasis research laboratory and collaborative clinical studies, to serve as a clinical interface with our basic Program Project in Thrombosia and Atherosclerosis. Specific projects in progress include: the diagnosis of the hypercoagulable state, and evaluation of the regulation of heparin, new assays for antiplatelet antibodies; studies of patients with altered hemostatic mechanisms, an examination of accelerated coagulation in diabetic retinopathy and in sudden deafness, the role of platelet amines in the vascular response to pulmonary embolism and subarachnoid hemorrhage, and the role of antiplatelet agents in coronary by-pass grafts.